4 
EXPERIMENTAL WORK WITH RAW ROCK PHOSPHATE. d1 
In 1889, however, the North Louisiana Experiment Station, at 
Calhoun, La.,1 began a five-year experiment to test the effect of vari- 
ous phosphatic fertilizers (alone and in combination with other ma- 
terials) on cotton. The results were published year by year, but 
in no bulletin is there a table giving the complete results for all five 
years, They have been consolidated by the authors in Table XX VI. 
Neither the size of the plots nor the character of the soil used in 
this experiment are mentioned, but the soil at the station is said to 
be on the whole sandy. The field was plowed during the winter 
of each year, the fertilizer drilled in in the spring, and the seed 
planted shortly afterwards. The crop was cultivated and hoed sev- 
eral times during each growing season. 
The climatic conditions during the third and fifth years are not 
described, but during 1889, and in July and August of 1890, droughts 
somewhat handicapped the crops. In 1892 late planting and ex- 
cessive rains seriously affected the yields for that year. 
TABLE XXVI.—Resulis obtained in the growing of cotton on plot No. 2 
(Calhoun, La.) (1889-1893). 
: Yield per acre of seed cotton. 
Applica- 
Fertilizer. tion per 
acre. 1889 1890 | 1894 1892 1893 
_—_— 
Pounds. | Pounds. | Pounds. | Pounds. | Pounds. | Pounds. 
PeueStep er 2 eae. a scwcea en =~ 80 1,520 1,810 | 1, 860 730 1, 250 
Dissolved bone black. .....-.--------- Back 160 1,630 1,770 1, 870 820 1, 240 
EEASa leet MTG fos eee 2 So ee ae c- 600 | 1,970 1, 800 1, 780 710 1,540 
Basal ELLE eG GT oo i ae pi ran G 2 2 133 2 2 215 2Q9. 2 
mussolved hone black ==. s.-.-..seeces =~ 2 - { aon thre 2 90 Breen ee 7920 1, 645 
TAOTOQ TS 222 Se eS se ee eee see er aae ease 80 1,390 1, 620 1,710 760 1,320 
PRETOIPHOSPH ALC hase seen ees = == sce 160 1,350 1,680 | 1,620 780 1,160 
BeasalgnextUnTe ss a= e soe es = eon - = == 600 1,720 1,870 1, 700 920 1, 450 
in 2 TERT. 2 ce eek oo esac ade See Sees Pee eoee nae 1,010 1,210 1,380 520 960 
Basal mixture !...-..--------------------- ae wads ihe Saat ; f 2 
ermdimhosphate. -..5=2-------+--j--------- { ae Viegas 50 » 760 | 1,735 680 1, 285 
Fore cas a eee eee 160 | 770 | 1,180| —_ 1,380 590 890 
ISeG0) Tai = 5 ae sense scenes 600 | 1,170 1,370 1,480 660 1,170 
TS yeet Tine ne 5a Ae ae eat ” ) é : ‘ Pf t ng : 
Pei et eee Pky i { ek | 1,305 2-1, 335 1, 545 700 1,130 
2 CUS vin ie ee 160 | 480 690 1,030 460 610 
ASS IEXGULG sae nee wl as see sea 600 | 920 1,100 | 1,190 560 1,100 
TEST) THINGS Sse ee ee ee ee 600 | leave? 
2 835 2 5 55 2 2 
PirrS 3: See a ee { 5G 835 1,015 1, 255 680 880 
IS GERRI SE S55 soe eos he Ss seco Sesose | w27 2 JAS aS | 330 630 730 380 470 
1 Basal mixture = 480 pounds cotton-seed meal and 200 pounds kainit. 
2 Average of two plots. 
Tt is apparent that the plots of this experimental field were far 
from uniform. Moreover, small applications of raw rock phosphate 
(160 pounds per acre) used on continual cotton without incorporat- 
ing more organic matter in the soil than was supplhed in the basal 
mixture employed in this experiment could hardly be expected to 
produce marked effects on the crop yield. 
1a. Agr. Expt. Sta., Bul. No. 27 (1889) (old series). Buls. Nos. 8 (1891) ; 16 (1892) 5 
26, 29 (1894) (new series). 
